The present invention is directed to focusing searches in hierarchical structures. More specifically, the present invention is directed to using region-sets in conjunction with keyword searches to focus those searches in hierarchical structures such as the World Wide Web.
With the proliferation of electronic information sources it has been necessary to provide searching capabilities to enable users to hunt for information of interest in large collections of electronic documents. It is well known to provide search engines for searching for pages of unstructured text on the World Wide Web, referred to herein as unstructured documents. Examples of such search engines include AltaVista, Lycos and others. These search engines do an effective job of finding many possible matches based on keywords provided by the user. However, the number of matches is often quite large and it is difficult to locate those few documents of particular interest within such a collection of matching documents.
Many of the search engines provide web directories, for example Yahoo (http://www.yahoo.com/) and Infoseek (http://www.infoseek.com) seek to address this problem of too many matches by providing topic-based hierarchical directories that allow users to navigate the topic.backslash.sub-topic hierarchy and pose keyword-based queries to locate documents classified under any specific topic of interest. While such directories are useful to locate a few matching documents, their utility is restricted. First, the act of classifying a rapidly growing collection of documents into specific topics is a human.backslash.computationally intensive task. Additionally, navigating the topic.backslash./sub-topic hierarchy is a very inflexible mechanism of focusing the search and does not allow users to pose keyword-based queries to locate documents classified into multiple topics. As a consequence of these two limitations, the documents that can be located using the web directories may not include a number of existing documents that would be of interest to the user.
It would be advantageous if a mechanism was provided for focusing web searches by augmenting keyword-based searches. In particular, it would be beneficial if a mechanism was provided that enabled the user to specify regions of the hierarchical structure as being of interest whereby the keyword-based search to be undertaken takes these region definitions into account.